1. Field of the Invention
The invention relates to a hydraulic control system.
2. Description of Related Art
A hydraulic control system including a mechanical oil pump, and an electric oil pump provided in parallel with the mechanical oil pump, is known (see, for example, Japanese Patent Application Publication No. 2007-113640 (JP 2007-113640 A)). The mechanical oil pump is driven with power of an engine, and the electric oil pump is driven with power of a motor when the engine is stopped.
In the hydraulic control system of JP 2007-113640 A, a through-hole used for removal of air is formed in a case of the electric oil pump, and air contained in the interior of the electric oil pump is discharged from the through-hole when the electric oil pump is driven, so that the hydraulic pressure can be promptly raised.